While scientists have not been able to prove its existence before, there is some evidence that metallic hydrogen does exist and a new scientific attempt – if successful – may provide another source of reliable fuel to mankind very soon
Hydrogen is commonly found as a gas in the atmosphere, but theoretically, it can exist in many states. For example, rocket engines use super cooled liquid hydrogen as a fuel, and if we cool hydrogen any further, we can freeze it to a solid form. Some physicists propound the fact that under extremely high pressure conditions, it is possible for hydrogen to take a new form and become a metallic solid. A team of physicists at the Harvard University have claimed to have exactly done that, but still many experts are doubtful. While it is relatively easy to get hydrogen in solid form by cooling it enough till it freezes, what scientists are trying to achieve is to obtain a metallic form of hydrogen that is solid in nature. Metallic hydrogen displays the usual properties of metal, like being shiny and able to conduct electricity. Scientists claim that metallic hydrogen could be stable even at a low pressure, but it has to be created at a very high pressure initially. If such a stable form of hydrogen can exist, it can be used as a superconductor or as a super-dense fuel for rockets.
Some scientists believe that metallic hydrogen is present in gas giants such as Jupiter, where there is extremely high pressure. The existence of metallic hydrogen in its core could explain the enormously powerful magnetic fields of Jupiter. However, creating the pressure that exists on Jupiter in a laboratory here on Earth can be a difficult task to achieve, and that’s probably why metallic hydrogen was never discovered before. A diamond enclosure is needed to achieve a pressure of this scale (approximately 72 million pounds per square inch). But even the hardest of diamonds can shatter at this pressure, if they are not perfectly smooth and without any flaws.
A team of scientists at the Harvard University have claimed to have bypassed this hurdle thanks to a new diamond polishing technique, and have used their apparatus to produce metallic hydrogen. Their findings have been published in the reputed journal Science. The team subjected one drop of liquid hydrogen to intense pressure from their diamond enclosure, and at a pressure of approximately 72 million psi, the hydrogen sample – which was initially clear – turned dark and then turned shiny. Scientists at Harvard say this is a clear sign that hydrogen possesses the capability to turn into a metallic solid. However, other scientists are still not clearly convinced. They are not able to judge how theHarvard team could actually achieve a pressure up to 72 million psi, and also say that the experiment was not repeated before the results were published. Also, the scientists disputing the results say that no experiment was carried out on solid hydrogen to see if it is able to conduct electricity and to test other properties of metals on the sample achieved. According to these scientists, the aluminium oxide coating on the diamond enclosure could have interfered with the results.
Whatever the case may be, the implications of this experiment are breath taking. Metallic hydrogen can behave as a superconductor at room temperature, and this could revolutionise the electric grid of today, in which nearly 20% of electricity is lost during transportation given the current technologies and materials used. Metallic hydrogen also has the potential to change our transportation system, making magnetic elevation of high speed trains possible. It can make electrical cars more efficient and radically improve the performance of all electronic devices, according to the team of scientists at Harvard University. Metallic hydrogen can also have a huge impact on energy production and storage techniques, as superconductors have zero resistance energy and hence they can be stored in superconducting coils and be used whenever needed.
Harvard scientists state that metallic hydrogen could also be the rocket fuel of the future. This can have widespread implications on rocketry and space travel as metallic hydrogen can be the most powerful propellant ever discovered. It takes a tremendous amount of energy to make metallic hydrogen, and if we find a system to convert this metallic hydrogen back into molecular hydrogen, a large amount of energy can be released. Due to this tremendous amount of energy released, rockets can be of single stage, carry more fuel and easily explore the outer planets. In addition, as the amount of fuel required is less in metallic hydrogen fuelled rockets, the quantum of payload that such rockets carry may also increase.
The possibilities are endless when it comes to metallic hydrogen and if our scientists succeed in bringing this metal to form, humanity can very well move beyond the next horizon of scientific development.